I just tried a different browser and that didnt work. I tried redownloading it and that didnt work. How do i check my cookies, caches, and proxies?"
Hey, so as far as proxies go, disabling them would only give more issues, at least that's what should happen. A proxy or proxy server is basically the communicator between your IP address and what you're telling your computer to do. As far as finding cookies and such, go to your browser and delete your history, when you choose to delete your history it should bring up something that asks what you want to delete, cookies being one of them, as well as the cache.
I know currently that there are some issues surrounding Feral Heart logins, I've witnessed this myself when at one point in time I was able to get into my account by simply typing in any password without using my actual one, but that was only on the forums and the issue is no longer present. The issue you're having could very well be something missing within your game files which effects the login, in which case you should completely get rid of everything to do with Feral Heart from your computer, not just uninstall it, and then download it once more and try again.
It could also be the order in which you're attempting to log in. Log into the play game portion before you even start Feral Heart, that gives it some time, then start up Feral Heart and attempt to log in, if that doesn't work then I'm not sure what the problem is. It could be your firewall, or it could be your computer doesn't properly support the game. Do you have windows? And if so, what version? Apple, I don't know much about and Linux is definitely far from my knowledge. What I do know is that if you're running it on a computer with windows Vista, you might have an issue.